Mast extension jib



Jan. 22, 1963 W. A. DAVIS ET AL MAST EXTENSION JIB Filed March l, 1961SSheets-Sheet l 5' Sheets-Sheet 2 w. A. DAvls ET AL MAST EXTENSION JIBJan. 22, 1963 Filed March 1, 1961 5 Sheets-Sheet 3 W. A. DAVIS MASTEXTENSION JIB Jan. 22, 1963 Filed March l, 1961 vUnited States IilinoisFiled Mar. 1, 1961, Ser. No. 92,672 6 Claims. (Cl. 212-64) Thisinvention relates to an apparatus -for facilitating the erection ofelevated structures. It more particularly relates to an extension jibderrick mounted atop the mast of the erection apparatus.

There has been developed a method of erecting elevated structuressupported on one or more columns employing a gin pole or mast atop whichis mounted a derrick device for lifting the structural elements forplacement, wherein the gin pole is jumped upward to succeedingelevations as the work progresses until a predetermined height isreached and the central column is then used to support a derrick with arotatable boom to nish hanging the steel in the upper portion of thetank. A mast and mast support system employed in this constructionfacility is described and claimed in U.S. Patent 2,754,012.

It is known in the art that a load on the boom portion of themast-mounted derrick shown in the aforementioned patent induces a stressdue to bending in the mast-mounting portion of the derrick which isproportional to the radius of the boom. According to the instantinvention there is provided a mast extension jib derrick which placesonly vertical loading on the mast and greatly increases the liftingcapacity of the derrick as well as the size and type of structures onwhich the aforementioned gin pole type of construction facility can beused.

In the drawings:

FIGURE 1 is a diagrammatic illustration of one embodiment of theextension ji'o derrick of this invention mounted on an illustrative ginpole;

FIGURE 2 is another embodiment of the extension jib derrick;

FGURE 3 is a schematic showing of one embodiment of the derrick devicewherein the lower anchor system for the jib stay is replaced by acounterweight;

FIGURE 4 is a cross-sectional view of the mast portion illustrating themeans for preventing vertical sway of the mast assembly and showing theattachment of the back stay to a mast jumper;

FIGURE 5 shows an alternative rigging arrangement for use on the jibderrick shown in FiGURE 1;

FIGURE 6 shows an alternative rigging arrangement for use on theextension jib derrick illustrated in FIG- URE 2;

FIGURE 7 illustrates an adjustable structural member connection betweenthe jumper support and jib stay connection point.

Referring to FIGURE l, the preferred embodiment of the invention isshown in elevation. The illustrative construction facility comprises theremovable support 10 which is adapted to be temporarily secured to thecentral column C of an elevated structure being erected. The bottomjumper mast support 16 for the mast comprises a tubular member ilthrough which extends a mast l2. 'Die tubular member il is provided withholes i3 matching corresponding holes in the mast i2 through which bolts14 are passed to secure the mast to the support. A pair of straps 15extend outwardly from the tubular member il near one end thereof and asimilar pair of straps '16 extend outwardly from the other end of themember 11. Secured to the outer ends of each of the straps by means ofhinges i7 are apertured plates i8, each of the plates being providedwith an opening 19 therein to receive an apertured lug 2d welded to thecolumn C.

Tapered pins 21 are passed through the holes in the lugs 20 to securethe member il to the column. To prevent side sway in the bottom mastsupport it), angle irons 22, as shown in FiGURE 4, are bolted orotherwise secured between each pair of legs 1'5 and 16 and to each angleiron 22 a coupling device 23 being so formed as to provide incooperation with the angle iron 22' flange a pair of openings 24 and 25is fastened to angle iron 22 by welding, bolting or the like. Theopenings 24 and 25 are adapted to register with similar openings 26 andZ7 formed by cooperation with the wall of column C and a correspondingcoupling device 28 welded to the column C. The coupling devices arejoined together yby pin 29.

Secured to the side of the member 11 adjacent its lower end is a sheave30 adapted to receive a cable 3'1 passing thereover and thencedownwardly around another sheave 32 secured to the bottom of the mast12. The cable then passes upwardly and is secured to an anchor fitting33 mounted, for example, on the lov/er end of the member 11.

Also a part of the mast support system is the upper jumper mast support34 adapted to receive the mast 12 therethrough and provided with straps35 similar to the straps 15 and 16, each strap being provided with ahinge 36 at its outer end and secured to an apertured plate 37. Theaperture in the plates 37 are adapted to receive apertured lugs 38therethrough, the lugs being welded to the column C. A pin 39 may beinserted through the lug 38 to secure the plate and hence the member 34to the column. A coupling device 4d, as previously described, isprovided on the member 34- to hold that member against side sway. Thelower end of the tubular member 34 is provided with a flange 42 adaptedto rest against the corresponding ange 43 provided on the upper end ofthe member 11. The member 34 is also provided with a second tlange 44adjacent its upper end against which a pin or bolt 45 extending throughan opening 46 in the mast can rest to secure the mast against verticalmovement when supported solely by the member 34- as hereinafterdescribed.

To carry out the instant invention, the upper portion of mast 12 isprovided with a derrick mounting section 50 consisting of a coredcylindrical socket 5l into which rits the pin 52 of the jib derrick yoketo provide a swivel mount to permit horizontal rotation for the jibderrick. Yoke 53 is a clevis-like arrangement having spaced upwardlyextending arms 54 which straddle the connection point 55 of the jibderrick which is shown generally at 55. The truss framework of the jibderrick consists of a chord member 57 rigidly braced by spacer strut 5Sand brace rods 59 and 6d which respectively connect the spacer strut 58with the load end and anchor end of chord member 57. An axle 6i passesthrough the arms 5d of bracket base 53 and the intermediate connectionpoint 55 on chord member 57 in order that the jib derrick 56 can bepivoted in its vertical plane. Rotatable sheave 62 is mounted at theload end of the chord member 57 of the jib derrick by means of pin 63. Adirection-changing sheave 64 is mounted on chord member 57 adjacent theconnection point '55 by means of bracket 65. At the anchor end of jibderrick 55 there is pivotally connected one end of ji'o stay 65. Jumpersupport l@ is provided with spaced mounting brackets 67' and 63' intowhich are fitted joint connections 69 and 7d formed by cylindrical hingepins 7l and 72 which allow tree horizontal rotation of the jib derrickand connector pins 73 and 74 which allow freedom from binding due tomisfabrication, and vertical adjustment oi the anchor system. One end ofstructural member 75 is connected to joint connector 69 while thecorresponding end of structural member-76 is connected to jointconnector 7d, The other end of the structural members 75 and '76converge to a common 3 point where they are interconnected. A jib stay66 is pivotally connected by link connectors 78 and l79 between theanchor end of the jib derrick 56 and the connecting point of thestructural members 75 and 76 to restrict vertical rotation of the jibderrick 56.

Lifting hook 80, located directly overthe centroid of the central columnC transfers the load lviacable 81 over sheaves V62 and 64|' to alifting'winch, not shown, located on lthe ground.

By employing the jib derrick of this invention, all the loading on themast 12 is vertical'an'd there is'no eccentricity developed with thisconfiguration from which bending stresses in the mast will result. Forexarnple, -the 'conventional'boom and mast' arrangement as shown in U.S.Patent 2,754,012 can'lift, as a maidmunnja piece 6 feet in diameter and16 feet long, and weighing' about 4,760 lbs. V-'Ihe mast extensionherein described is not limited dimensionally to any sie orweight liftbuffer a corresponding sized jib derrick, constructed infaccor'da'n withthis'invention, a lift of 10,00() lbs. Acan be triade.

' Although'the preferred embodiment 'of jib'derrickis Y shown in FIGUREl, there are a variety of modifications sof this Astructure Vwhich canbe made. For simplicity;'tlie same numbers as used above will -beemployed in describing equivalent membersrin the fllowing variations.For example, thedirection-changi'ng shear/e643` as Ish'ivn in FIGURE 5,can be placed at the'ancho'r vend of the jib derrick 56, or structuralmembers 77 'or 78 liii-the lwer anchor system, as vshown in FIGURE 7, orVanchor cable 66 can beniade to be 'adjustableso that the'radiusgo'f-the load side'of the jib derrick can be readily altered.Usually, only one radius is needed for each column in-` stallation inorder that each new section of column C hangs directly over the sectionpreviously placed. Y

Another modification which can Abe made involves Vthe coniiguration ofthe jib derrickY framework as shown in FIGURES 2 and 6. In this assemblythe chord member 56 of the framework truss is replaced by dihedral strutrods -85 and S6. Suitable rod connectors 87 and 88 are used'to connectthe inner ends of the rods 85 and 86-to the spacer strut'r58 and basevbracket 53 and -the outer ends of the rods 85 and 86 with brace rods 59and 60, as well as provide a sheave journal -at the load end and anchorend of the framework depending upon the selected ldesign. Anyarrangement of structural members which will supportthe applied load issatisfactory. In Vstill another embodiment, a counterweight such asshown schematically in FIGURE 3 replaces the lower anchor system.

In operation, lifting hook 80 coupled with a suitable lifting device,such as conventional lifting clamps 90, is attached to the column pieceto be lifted. The load falls, although shown as a single fall, can bemultiple parts to form a load block having a'substantial mechanicaladvantage. While the lift is being made, tag lines are used to swing thenew column section into place. As the load portion of the jib mastextension is being swung into place, the anchor portion being so mountedalso rotates horizontally through the same arc. Therefore, the load onthe jib mast section of the Yderrick isV always vertical.

The jumping operation of the erection derrck employing the instantinvention which is the subject of U.S. Patent 2,754,012 is carried outas follows:

With the mast support 11 and 34 secured to thecolum'n fC by the mastsupport attachment means described above, the jib derrick 56 can beemployed to lift a second column section. The initial columninstallation is generally made using a truck-mounted crane or the like.The derrick can then be rotated on the mast 12 to swing the secondsection into position over the installed column section C in whichposition it may be secured thereto. When it becomes necessary to"jumpthe mast, the cable of the mast extension ssecured to the fitting 91attached to themast supportV 34 and the fastening devices which securethe" mastvsl'lpport tothe column C are removed.

The upper mast support 34 is then lifted upwardly by means of the jibderrick to the new position where it is secured to the upper portion ofthe column section by attachment means previously -provided on the upperpart of the new column extension. The rnast may be then secured tothefupper mast support 34 -by means of the pin and aperture device 45and 46 previously described. The cable on the derrick is Vthen releasedfrom the fitting 91 and secured to a fitting 92 attached to the member11.`

Bolt 14 is'then withdrawn and the various pins which secure the member11 to the column C are removed and the jib derrick 56 employed to liftthe mast'support 11 to the new position wherein it is secured to theattachment means previously attached to the top of the new columnsections. By removing the pin-45 whichsecures the lmast to the uppermast support 3,4 and by` pulling on the cable 31, the mast is then slidupwardly through the mast supports11and34 until it reaches theipositionrelative thereto which it had previously occupied, whereupon the, bolt14 and the pin 45 are -reinserted and the mast and `derrick are thenready for use to hoist another column section into position, Succeedingcolumn sections may be elevated in vposition by moving ltheYsupportspmast and derrick upwardly as just described. It is apparent,therefore, that other mast structures and jumperlfgniast support systemscan be used in conjunction with the jib derri'ckgf this invention. l i,Y

The jib derrick can-be constructed from conventinal materials-ofconstruction. In selecting the derrick design, a truss framework shouldbe employed which will provide a -load armhaving substantially thesameextentl as the anchor arm; however, variations in length can be usedIfor different erection problems such as large diameter columninstallations. In the event thatMthe-jib yderrick 56 is arranged suchthat the load arm has a different radius than the anchor arm, provisionsmust be made, as shown in 'FIGURE 2,1for arranging the load falls so asto permit the jib derrick to exert/a force on the mast structuresubstantially coaxial with the longitudinalaxis Yof the mast. It will benoted that the jib derrick 576 shown,v in FIGURE 2 has `been pivoted ina vertical plane so that the load arm and anchor arm do not have thesame'eitf tent. VIn, the jibderrick arrangement shown in FIGURE 2, hookis secured to a sheave block 95. The loadfall 81 is reeved through thesheave block `95 and itsvterminal end secured to lug 96 of the sheavejournal at the load end of the framework. By securing the load fall -81in this manner, a proper balancing of the forces canobtainY to effecttheobjectives ofY this invevntion which provides a jib derrick whichwill eliminate stresses due to bending in the mast structure of aconstruction facility.

While We have shown and described certain embodiments of our invention,it is to be understood that it is capable of many modifications.Changes, therefore, in the method, construction and arrangement may bemade without departing from the spirit and scope of the invention asdisclosed in the appended claims.

What isclaimed is:

1. In a masted apparatus for facilitating the erection of an elevatedcolumn, a mast-mounted jib derrick comprising a unitary truss frameworkhaving a load portion and an anchor portionoppositely extending `from anintermediate mounting pivot, said mounting pivot adapted to permit therotation of said truss framework in asubstantially horizontal plane, arotatable sheave journalled in the free end of said load portion, adirection-,changing sheave mounted on said framework adjacent ysaidanchor portion, and means vertically depending from the terminal end ofsaid anchor portion for anchoring said anchor portion to resist theupward displacement thereof.

`2. In a masted apparatus for facilitating the erection Vof an elevatedcolumn, a mast-mounted'jib derrick comprising a unitary truss frameworkhaving a load portion andv an anchor portion oppositely extending Yfroman intermediate mounting pivot, said mounting pivot adapted to permitthe rotation of said truss framework in a substantially horizontal planeand including a yoke portion to which said framework is pivotallyattached to permit the angular displacement thereof in a vertical plane,a rotatable sheave journalled in the free end, a directionchangingsheave mounted on said framework adjacent said anchor portion, and meansvertically depending from the terminal end of said anchor portion foranchoring said anchor portion to resist the upward displacement thereof.

3. In a masted apparatus for facilitating the erection of an elevatedcolumn, a mast-mounted jib derrick comprising a unitary truss frameworkhaving a load portion and an anchor portion oppositely extending from anin termediate mounting pivot, said mounting pivot adapted to permit therotation of said truss framework in a substantially horizontal plane andincluding a yoke portion to which said framework is pivotally attachedto permit the angular displacement thereof in a vertical plane, arotatable sheave journalled in the free end, a directionchanging sheavemounted on said framework adjacent said anchor portion, and meansvertically depending from the terminal end of said anchor portion foranchoring said anchor portion to resist the upward displacement thereofincluding a downwardly extending jib stay.

4. In a masted apparatus for facilitating the erection of an elevatedcolumn, a mast-mounted jib derrick comprising a unitary truss frameworkhaving a load portion and an anchor portion oppositely extending from anintermediate mounting pivot, said mounting pivot adapted to permit therotation of said truss framework in a substantially horizontal plane andincluding a yoke portion to which said framework is pivotally attachedto permit the angular displacement thereof in a vertical plane, arotatable sheave journalled in the free end, a directionchanging sheavemounted on said framework adjacent said anchor portion, and meansvertically depending from the terminal end of said anchor portion foranchoring said anchor portion to resist the upward displacement thereofincluding a downwardly extending jib stay adapted to be rotatablyattached to said masted apparatus and substantially remain in thevertical plane of said jib derrick.

5. In a masted apparatus in accordance with claim 4 in which said jibstay is adjustable.

6. In a masted apparatus for facilitating the erection of an elevatedcolumn, a mast-mounted jib derrick comprising a unitary truss frameworkhaving a load portion and an anchor portion oppositely extending from anintermediate mounting pivot, said framework comprising a parallelogramtruss having a dihedral strut assembly and an opposed dihedral braceassembly, said mounting pivot adapted to permit the rotation of saidtruss framework in a substantially horizontal plane and including a yokeportion to which said framework is pivotally attached to permit theangular rotation thereof in a Vertical plane, a rotatable sheavejournalled in the free end, a directionchanging sheave mounted on saidframework adjacent said anchor portion, and means vertically dependingfrom the terminal end of said anchor portion for anchoring said anchorportion to resist the upward displacement thereof including a downwardlydepending jib stay adapted for attachment to said masted apparatus.

References Cited in the tile of this patent UNITED STATES PATENTS

1. IN A MASTED APPARATUS FOR FACILITATING THE ERECTION OF AN ELEVATEDCOLUMN, A MAST-MOUNTED JIB DERRICK COMPRISING A UNITARY TRUSS FRAMEWORKHAVING A LOAD PORTION AND AN ANCHOR PORTION OPPOSITELY EXTENDING FROM ANINTERMEDIATE MOUNTING PIVOT, SAID MOUNTING PIVOT ADAPTED TO PERMIT THEROTATION OF SAID TRUSS FRAMEWORK IN A SUBSTANTIALLY HORIZONTAL PLANE, AROTATABLE SHEAVE JOURNALLED